WASHINGTON, D.C – As soon as left-hander Cliff Lee pulled up and gestured to his elbow after throwing a pitch Thursday against the Washington Nationals, a bleak season became even more disheartening for the Philadelphia Phillies.

Lee lasted only 2 2/3 innings in his third start off the disabled list and was looking more like his old self when one pitch likely ended his season in the Phillies' 10-4 win against the Nationals.

Lee was put on the 15-day DL after the game and will be evaluated Friday after being diagnosed with a left flexor pronator strain – the same injury that put him on the DL for two months until July 21. He will then see a doctor Saturday in Washington, D.C. Left-handed reliever Cesar Jimenez was called up from Triple-A Lehigh Valley to take Lee's spot.

"It's obviously a frustrating moment," Lee said. "I had an arm injury that I've never had before, or anything close to it. I missed two months. I came back and on my third start, it's back. Obviously that's frustrating, especially when it was progressing well. It was all but gone. It was out of my mind."

Lee said he first felt it when warming up before the game and it never fully went away. He noticed it got worse five to six pitches before his final pitch. Lee acknowledged he probably threw his last pitch of the season and did not rule out surgery to fix the problem.

"It was there every throw," Lee said. "I just felt like if I kept throwing something was going to snap. I wanted to make sure that didn't happen."

On the first pitch of Denard Span's at-bat with a runner on second and one out in the third, Lee threw an 85-mph cutter that was called a ball. It would be his last pitch of the game as Lee cursed and pointed to his left elbow. Phillies trainer Scott Sheridan and manager Ryne Sandberg came out to look at Lee, and he was immediately removed from the game.

After two sub-par outings, Lee was pitching more like is old self, limiting the Nationals to one hit while not issuing a walk and striking out four batters on 31 pitches (24 strikes) in 2 2/3 innings.

"He was actually throwing the ball well," Sandberg said.

The Phillies' offense came alive after Lee exited the game, scoring five runs and sending 10 batters to the plate in the fourth against Nationals left-hander Gio Gonzalez (6-7). Grady Sizemore hit a two-run double to put the Phillies ahead 2-0. Domonic Brown and Chase Utley each drove in a run on a fielder's choice in the inning while Ben Revere recorded an RBI single to help build a 5-0 lead.

The Phillies added two runs in the sixth and three runs in the eighth, finishing with 17 hits.

Washington cut into the Phillies' lead, scoring a run in the fourth on Wilson Ramos' RBI single with two more runs in the fifth thanks to Span's two-run double with the bases loaded off Mario Hollands. In the seventh, Danny Espinosa cut Philadelphia's lead to 7-3 with his run-scoring single against Jake Diekman.

The Nationals brought the game-tying run to the plate in Jayson Werth against reliever Ken Giles, who struck him out with a 100-mph fastball.

Although the Phillies held off the Nationals, Lee's injury cast a shadow over it. The Phillies already have a good potential replacement lined up on Lee's turn in the rotation. Right-hander David Buchanan, who filled in for Lee during his earlier stint on the DL. started for Triple-A Lehigh Valley Thursday throwing 7 1/3 innings allowing one run on seven hits with a walk and five strikeouts.

The only positive thing to potentially come from Lee's injury is the likely opportunity Buchanan will get to prove he deserves to be part of the Phillies' future rotation. Buchanan, 25, made his big-league debut this season after Lee went on the DL. In 10 starts, Buchanan posted a 5-5 record and 4.40 ERA. He allowed three runs or fewer in seven starts.

The smart thing for the Phillies to do would be to immediately shutdown Lee for the rest of the season. Although he would pass through waivers, it would seem impossible for Lee to be healthy by the time the Aug. 31 waiver trade deadline arrives. Since Lee is owed at least $37.5 million the next two seasons, making sure he is 100 percent healthy should be the Phillies' top priority.

Any turnaround the Phillies hope for next season will need a healthy Lee, if he can't be traded for a major-league ready player during the offseason.

"Obviously I'm worried about it," Lee said. "It came back, so that's not good. I don't think it's a larger problem. I think it's just the original thing. It was never fully gone."

Papelbon has faith

Having found himself still a Phillie at the 4 p.m. trade deadline Thursday, Jonathan Papelbon said that was fine by him.

The veteran stopper was viewed as a top candidate to be dealt, and had said he wouldn't mind landing with a contender.

Instead, he remained – for the time being anyway – with the last-place Phillies.

"I think we have a phenomenal bullpen here in Philadelphia and I would like to be a part of that," Papelbon said. "Nothing wrong with being a part of a great bullpen."

He added that he likes the direction of the team, despite evidence to the contrary.

"I think there is a reason why nobody got traded," Papelbon said. "I think Ruben [Amaro Jr., the GM] has faith in the guys in this clubhouse hopefully. Obviously there are things that need to be turned around for next year."

That, he added, is as simple as playing "more consistent baseball."

Papelbon has been among the Phillies' few consistencies, compiling a 1.83 ERA while piling up 25 saves in 28 opportunities, hence his trade value. But he is signed for $13 million per year, with vesting options, through 2016.

He did say, however, that he has no interest in being anything except a closer, even if it meant being on a World Series team.

"I don't set up," he said. "And you should know that . . . The chance to win a World Series is with me closing. Period.''

Gonzalez hit hard

Phillies fans have often lamented the trading away of Gio Gonzalez, the Nationals pitcher who entered Thursday's start with a 76-54 record and 3.59 ERA in seven big-league seasons, highlighted by his 21-win 2012 effort. Gonzalez is the former White Sox first-round draft pick who spent 2006 in the Phillies' organization at Double-A Reading after being acquired in a trade for Jim Thome, only to be shipped back to Chicago in the disastrous Freddy Garcia deal.

Thursday's start against the Phillies, however, was one of the worst of 2014 for Gonzalez, whose ERA climbed to 3.88 after he allowed five runs on eight hits in just 3 2/3 innings. The Phillies scored all five runs in the fourth inning, when they had five hits, including Grady Sizemore's two-run double.

Extra innings

Ryan Howard did not start Thursday because, manager Ryne Sandberg said, "This guy [Gonzalez] is tough on him . . . Mario Hollands kept his disastrous run of relief going Thursday, allowing three runs on four hits, with a walk, wild pitch and hit batter, in 1 1/3 innings. He has now allowed 13 earned runs in 7 2/3 innings over his last eight games.

Contact Meghan Montemurro at mmontemurro@delawareonline.com and follow on Twitter at @M_Montemurro. Kevin Tresolini contributed to this report.